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In some cases this may > reduce performance, but high performance has not been a requirement so far > for CoW-based atomic writes. > > Signed-off-by: John Garry [...] > ---->8------ > > This is far from ideal, but I think that it should stops the hangs - having > the kernel hang is intolerable. Thanks. I applied the patch on top of xfs/for-next branch commit 0ca15a1a1151, then repeated the test case 100 times on top of the kernel. I did not observe the hang. This patch looks avoiding the hang.